Determinants of successful direct current cardioversion for atrial fibrillation and flutter: the importance of rapid referral.

Direct current (DC) cardioversion is an effective means of restoring sinus rhythm in patients with atrial fibrillation or flutter; however, the existing literature contains conflicting evidence on which factors are useful predictors of success. In a study of 171 patients undergoing DC cardioversion, we found that duration of arrhythmia prior to DC cardioversion was the only significant predictor of both successful cardioversion and subsequent maintenance of sinus rhythm (P < 0.001). Rapid DC cardioversion after the onset of atrial fibrillation or flutter significantly increases the likelihood of a successful outcome in both the short-term and long-term.